Why can't iphone4 send text messages with Unicom card?

If you can't send or receive SMS, please follow the following steps to troubleshoot:

1. Look at the upper left corner of the iPhone display, make sure you are in a strong signal area, and make sure the flight mode is off. If the signal is weak, try moving to another location. If you are indoors, try going outside or moving to the window.

2. Please consult the wireless operator to check whether your SIM card status is normal.

3. Be sure to click on the text input field at the bottom of the screen to bring up the keyboard. Before you start typing, the "Send" button is always displayed in gray. After you enter the text, the "Send" button is displayed in bright color and can be clicked.

4. If you can't click Send after entering the text, the "Send" button is still gray. Please set > SMS > turn off the display of the subject bar.

5. If you try to send a short message to multiple recipients, and you manually enter each number instead of using the address book list, make sure to separate each number by pressing a line break instead of a space.

6. If you still can only receive messages, you can't send them.

After eliminating the above problems, you can use the internal command to query and edit the SMS center number:

Set SMS center number: dial *5005*7672*+86 SMS center number # with iPhone;

Delete SMS center number: dial ##5005*7672# with iPhone.

Inquire about the set SMS center number: dial *#5005*7672# with iPhone.

When using the internal command, first use the delete command, and then set the SMS center number.

Note: The set SMS center number is generally similar to the mobile phone number after +86. For example, the correct number setting method of Beijing Unicom 186 is * 5005 * 7672 *+86130112500 #.